Anomalous Lense–Thirring precession in Kerr–Taub–NUT spacetimes

Chandrachur Chakraborty

doi:10.1140/epjc/s10052-015-3785-y

Chandrachur Chakraborty

Open Access

https://doi.org/10.1140/epjc/s10052-015-3785-y

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Abstract

Exact Lense-Thirring (LT) precession in Kerr-Taub-NUT spacetime is reviewed. It is shown that the LT precession does not obey the general inverse cube law of distance at strong gravity regime in Kerr-Taub-NUT spacetime. Rather, it becomes maximum just near the horizon, falls sharply and becomes zero near the horizon. The precession rate increases again and after that it falls obeying the general inverse cube law of distance. This anomaly is maximum at the polar region of this spacetime and it vanishes after crossing a certain `critical' angle towards equator from pole. We highlight that this particular `anomaly' also arises in the LT effect at the interior spacetime of the pulsars and such a signature could be used to identify a role of Taub-NUT solutions in the astrophysical observations or equivalently, a signature of the existence of NUT charge in the pulsars. In addition, we show that if the Kerr-Taub-NUT spacetime rotates with the angular momentum $J=Mn$ (Mass$\times$Dual Mass), inner horizon goes to at $r=0$ and only {\it event horizon} exists at the distance $r=2M$.

Highlights

The Lense–Thirring (LT) precession [1] is an important phenomenon in General relativity as well as in relativistic astrophysics
We have shown that the LT precession in KTN and Taub– NUT spacetimes are quite different than the LT precession in other spacetimes
The exact frame-dragging effect inside the rotating neutron star has recently been derived and discussed in detail by Chakraborty et al [15] but this is the interior solution of the Einstein equation, not the vacuum solution

Summary

Introduction

The Lense–Thirring (LT) precession [1] is an important phenomenon in General relativity as well as in relativistic astrophysics In this phenomenon the locally inertial frames are dragged along the rotating spacetime due to the angular momentum of the stationary spacetime. Lynden-Bell and Nouri-Zonoz [8] were the first to initiate investigation of the observational possibilities for NUT charges or (gravito)magnetic monopoles They have claimed that the signatures of such spacetime might be found in the spectra of supernovae, quasars, or active galactic nuclei. The KTN spacetime is a stationary and axisymmetric vacuum solution of Einstein equation This spacetime consists of the Kerr and NUT parameters.

Lense–Thirring precession in Kerr–Taub–NUT spacetime

Results

Summary and discussion